> The figure is equivalent to the size of the US and Japanese economies combined.

The author of the article apparently does not understand the difference between capital, money at rest, and GDP, money in motion, a yearly measure.

I suspect the author understands it just fine and used the comparison to give readers a sense of scale.

Can you imagine $21T? I can't. If you tell me that it's as much money as the GDP of two fairly successful countries (implied: for a year) I can understand its scale a little more.

Nothing in the article suggested that your assertion is true. I may be, but what's in the article is simply a rhetorical device to help give scale to what is, for most people, an imaginary number.

It's a terrible way to compare the two things, since you're fundamentally measuring something completely different.

If you really want to compare it to something, why not compare it to the public debt the US holds, which the suggested number would do more than fill (current public debt is somewhere a bit north of 15T); especially since the argument is made by the people who instigated the study that taxing this figure could balance the books (it probably couldn't; since only a fraction of that is actually subject to US taxes, and most of it would probably only end up being due for capital gains taxes anyway -- not that it wouldn't go a long way).

I wonder is this why central banks are having to print money if this amount is being stashed away and not allowed to circulated in the economy.

... and if it were made to circulate, we'd have hyperinflation and it would quickly become worthless. But I doubt that it can be made to circulate. I doubt that this is cash.

Is this "real" money, or is this 300X-leveraged financial instruments that could evaporate if someone breathes too hard.